Containers



y 5, 1964 J. G. SHERLOCK ETAL 3,131,845

CONTAINERS Filed June 12, 1962 \NvENToRs JOHN G SHERLOCK HAROLD J. DRAPER ATTORNEYS United States Patent Ofi ice 3,131,845 Patented May 5, 1964 3,131,845 CONTAFNERS John Gerrard Sherlock, Feltham, and Harold John Draper, Ruislip, England, assignors to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed June 12, 1962, Ser. No. 201,896 Claims priority, application Great Britain June 16, 1961 4 Claims. (Cl. 229-) The present invention relates to containers of the kind having an end wall (referred to herein for convenience as the bottom) and side walls or a side wall so shaped as to allow the containers to be nested or stacked one within another for transit or storage. The side walls are normally tapered at a shallow taper angle. Such containers for convenience will be referred to in the present specification as containers of the stated kind.

The present invention consists of an open mouthed container of the stated kind including at least one protuberance formed in the bottom of the container engageable with the bottom of a similar container nested within it to prevent the side walls of the containers being jammed together. Preferably such a protuberance projects inwards into the container. The effective height of the protuberance must be correctly related to the thickness and taper angle of the walls, to prevent jamming.

The invention has particular application to containers formed by such processes as drawing, or vacuum or pressure forming from sheet synthetic plastic material such as polystyrene. Such containers are commonly used for drinking cups of the throw away expendable type or are provided with lids or closure members for use as containers for drinks, ice cream and so on. Before use the containers are almost invariably arranged for purposes of economy of storage space in a stack with one nested inside another. When so arranged it is of particular importance that two or more containers do not get jammed together as such jamming results, for example, in delays necessary for separating the jammed containers, or in cases where such containers are filled by automatic operating machines or are dispensed by beverage vending machines, in damage to the machine or in failure of the machine to operate.

By providing a protuberance or protuberances in the bottom of a container according to the present invention, jamming of the containers is unlikely and so the difiiculties associated with such jamming are obviated or minimised.

The formation of such a protuberance projecting from one side of the bottom of a thin-walled container of necessity results in a corresponding depression or cavity being formed in the other side of the bottom and it should therefore be appreciated that in order to minimise the risk of a protuberance on one container entering the cavity formed by a protuberance of a second container nested within the first to cause jamming of the two containers, the protuberances should be so shaped that either a protuberance cannot enter the cavity formed by another or, if a part of a protuberance can enter the cavity of another, then no jamming can take place between the cavity walls and the protuberance positioned within the cavity.

In one preferred form of the invention the protuberance is of a cylindrical form with its side or sides extending parallel with the axis of the container and thus entry of a protuberance of one container into the cavity formed by a protuberance in another is prevented by the thickness of the material forming the bottom. Such a cylindrical protuberance, in cross-section, may be in the form of a polygon but preferably the protuberance has a circular cross-section.

The provision of parallel sides in the protuberances is an advantage in containers formed in a mould in that such a provision permits a container to be readily removed from the mould after its formation. A protuberance may, of course, be such as to have sides which diverge on leaving the bottom of the container so that the innermost parts of the protuberance will be unable to enter the mouth of a cavity formed by another but such containers can only be removed from a mould in which they are formed without damage if, for example, the material from which the containers are made is such as to allow this (for example, by reason of its resiliency) or the mould is so designed that the boss or plug within the mould and about which the protuberance is formed can be collapsed and drawn out of the cavity after the container has been formed and prior to the removal of the container from the mould.

The invention may be performed in various ways and some specific embodiments will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a sectional side elevation through an open-mouthed plastic cup; and

FIGURE 2 is a sectional view of a modified form of cup, showing two such cups nested one in the other.

In the cup illustrated in FIGURE 1 the side wall 10 is tapered at a small angle and a number of such cups can thus be nested or stacked, one within another, for transit or storage, or used in automatic dispensing or filling machines. The side wall is formed with a number of shallow parallel circumferential ribs or grooves 9 which act primarily as stifiening members. If the base of such a cup is made flat, the cups would tend to jam when nested. In this example of the invention, the base of the cup is formed with a shallow depression 11 which results in an annular downwardly projecting rim 12 and acts to stiffen the base. It will be noted that since the depression is shallow and the walls of the depression are substantially horizontal the depression will not in itself support one cup spaced above a cup in which it is nested. In the centre of the base there is formed a cylindrical protuberance 13 having parallel vertical side walls 14. This protuberance will support one cup with its base appreciably above the base of a lower cup so as to prevent jamming. The effective vertical displacement will be determined by the height of the vertical walls 14 and not by the total height of the crown of the protuberance above the lower part of the base.

In the form of cup illustrated in FIGURE 2, the side wall 15 is tapered at a small angle and in this case the base is flat and is provided with a central circular protuberance 16 having a side wall 17 which flares upwards and outwards at a small angle. The angle is shown exaggerated in the drawings to illustrate its effect in preventing the protuberance in a lower cup from entering into the corresponding depression in the base of a cup above it. In practice since the cup is moulded, there is a practical limit to the angle of flare which will be ap proximately 1 or 1 /2 In the examples illustrated, a single central protuberance is formed in each cup, but it will be understood that two or more protuberances may be formed in the end wall.

What we claim as our invention and desire to secure by Letters Patent is:

1. A pair of identical nested open-mouthed thin-walled containers each of integral formation from a plastic material, and each having an end wall and diverging side walls with an axially inwardly directed generally cylindrical protuberance in the end wall, an upper shoulder at the inner end of the protuberance, and a lower shoulder where the protuberance is united with the end Wall, the lower shoulder of the nesting container resting on the upper shoulder of the container in which it is nested, and radial clearance being maintained between the side walls of the two'containers.

2. A pair of containers as claimed in claim 1 including a flat annular portion of the end wall surrounding the protuberance and uniting it with the side walls.

3. An open-mouthed thin-Walled container of integral formation from a plastic material having an end Wall and shoulder where the protuberance is united with the end 1 Wall, the upper shoulder extending radially from the axis of the cup to a greater distance than the lower shoulder.

4. An open-mouthed thin-walled container as claimed in claim 3 including a flat annular portion of the end wall surrounding the protuberance and serving to unite the protuberance with the side walls.

References Cited in the file of this patent UNITED STATES PATENTS Harrison May-2, 1 961 2,988,258 Witzke June 13, 1961 FOREIGN PATENTS 530,975 Belgium Oct. 31, 1954 

1. A PAIR OF IDENTICAL NESTED OPEN-MOUTHED THIN-WALLED CONTAINERS EACH OF INTEGRAL FORMATION FROM A PLASTIC MATERIAL, AND EACH HAVING AN END WALL AND DIVERGING SIDE WALLS WITH AN AXIALLY INWARDLY DIRECTED GENERALLY CYLINDRICAL PROTUBERANCE IN THE END WALL, AN UPPER SHOULDER AT THE INNER END OF THE PROTUBERANCE, AND A LOWER SHOULDER WHERE THE PROTUBERANCE IS UNITED WITH THE END WALL, THE LOWER SHOULDER OF THE NESTING CONTAINER RESTING ON THE UPPER SHOULDER OF THE CONTAINER IN WHICH IT IS NESTED, AND RADIAL CLEARANCE BEING MAINTAINED BETWEEN THE SIDE WALLS OF THE TWO CONTAINERS. 